Since solid-state NMR spectroscopy is at an early stage in its applications to proteins, additional development of spectroscopy is essential. The Resource is involved in all aspects of the development of instrumentation and techniques for solid-state NMR spectroscopy, much of which involves the most fundamental elements of spectroscopy. We have made great strides during the past year in the development of three- and four-dimensional solid-state NMR experiments. The recent development of the PISEMA procedure which gives very high resolution heteronuclear dipolar spectra has been the cornerstone of the new pulse sequences. The three-dimensional experiment that correlates 1H chemical shift, 1H-15N dipolar coupling, and 15N chemical shift has many uses, including higher resolution in solid-state NMR spectra of single crystal and oriented samples and the simultaneous characterization of the magnitudes and orientations of the principal elements of the three spin-interaction tensors. Here, a variety of peptide linkages are needed to identify the sequence dependence of the properties of the tensors, and synthetic peptides containing these are provided through the collaboration with the group at the University of Massachusetts. For example, the availability of large single crystals of a peptide with two labeled peptide bonds was crucial for the development of the first four-dimensional solid-state NMR experiment.